Grinding-machine.



P. H. ROOT.

GRINDING MACHINE.

APPLIGATION FILED MAR. 1, 1913. 1,077,306, Patented Nov. 4, 1913.

2 SHEETSSHEET 1,

,YjIUGZZZ OT' P. H. ROOT.

GRINDING MACHINE.

I APPLICATION TILED MAR. 1, 1913. 1,077,306, Patented N0v.4, 1913.

2 SHEETS-SHEET 2.

7(6. JZW/ g(%% with respect to the grinding disk.

reciprocating the workholder, positive drivprovide a slmple and effective form of work widths.

as consisting in certain novel details of contially along the line 33 of Fig. 2, with the portion of the workholder to which the work is secured; Fig. 5 is a bottom view of the PERCY H. noor, on

GRINDING-MACHINE.

Specification of Letters Patent.

PLYMOUTH, OHIO.

Application filed March 1, 1913. Serial No. 751,415.

To all whom it may concern:

Be it known that I, PERCY I-I. Roor,a citizen of the United States, residing at Plymouth, in the county of Richland and State of Ohio, have invented a certain new and useful Improvement in Grinding-Machines, of which the following is a full, clear, and exact description. 7

This invention relates to grinding machines of the general type disclosed in my prior patent for grinding machine, No. 1,044,575, issued Nov. 19th, 1912.

he invention relates particularly to the workholder and t0 the means for reciprocating the same, and has for one of its ob-- jects to provide between the workholder and the rotary grinding disk, or the spindle to which the disk is secured, reciprocating mechanism by which the workholder is positively actuated, and in timed relationship Further, the invention aims to provide for mg or actuating means, which does not require a reciprocating arm or other device which extends about or around the periphery of the grinding disk from below the disk, where the power is applied, to a point above the disk or at the side thereof, at which the workholder is reciprocated.

In another respect, the invention aims to holder which holds the work down onto the face of the grinding disk, and which has a range of adjustment to enable the holder to receive or accommodatework of varying dimensions, especially cutter blades of various My invention may be briefly summarized struction and combinations and arrangements of parts which will be described in the specification and set forth in the appended claims. 7

In the drawings, Figure 1 is a top plan view of a grinding machine embodying my improvements; Fig. 2 is a side view of the same; Fig/ 3 is a sectional 'view substangrinding disk shown in elevation; Fig. 4 is a top plan vlew on an enlarged scale of a same with the work removed from the holder; Fig. 6 is a view, s1milar to 4, showing a slight modificatlon, and wlth the Patented Nov. 4, 1913.

work removed from the holder; Fig. 7 is a sectional view substantially along the line 7 7 of Fig. 4:, and Fig. 8 is a similar sectlonal view substantially along the line 88 of Fig. 6.

Referring now to the drawings, it will be seen that the machine includes a base 10 which in this case consists of a pair of parallel bars or beams, and a suitable frame or framework including a plurality of upright substantially V-shaped brackets 11, which are secured to the base and are connected together by suitable bracing strips 12. The work is ground upon the top face of a horizontal rotary grinding disk 13, which is preferably a metal disk adapted to be provided on its upper face with a grinding paste for grinding the work, which may consist of blades of various kinds of cutting implements. This'grind'ing disk is secured to a vertical spindle 14: which projects above and below the disk, the part above the disk being provided for a purpose to be presently re ferred to, and the part below being mounted for rotary movement in bearings 15, of one of the brackets 11.

It is immaterial, as far as the present in- I vention is concerned, in what manner or by what specific mechanism the disk 13 is driven. In the present case, however, the disk rest-s and. is pair of rollers 16 and 17 the latter of which is secured to a driving shaft 18 having loose and tight pulleys 19, which may be engaged in the well known manner by a driving belt. The grinding disk is therefore driven frictionally or by the frictional driving engagement of the wheel 17 on the lower side or face of the grinding disk. The outer end of the shaft may be provided with a roughgrinding disk 20 on which the work may be ground preliminarily to the grinding which is done on the grinding disk 13. While the work is rough ground on the grinding disk 20, it may be supported on a suitable workpartly supported upon aholder 21, carried by an arm 22, secured to the frame work of the machine.

Above the g'rindingdisk is a horizontal reciprocating workholding bar or slide 23,

which extends across the top of the grinding disk in the center plane thereof. This bar 23 is supported for reciprocating movement lower side, yieldable elastic spring strips or arms 25, to the free ends of which are pivotally secured holders 26, which hold the work 27 during the grinding operation. These spring arms 25 press the work down onto the face of the grinding disk and hold the reciprocating bar 28 up against the rollers 2a. The construction of the work holding members 26 will be explained more fully later. It will be observed by reference to Figs. 1 and 3, that the reciprocating bar 23 is provided, substantially midway between its ends, with an enlarged portion having an elongated slot through which the upper part of the spindle proj ect-s, and which allows the bar to be reciprocated with reference to said spindle and grinding disk 13.

In my prior patent above referred to, the work holding rod or bar is reciprocated by mechanism including a friction drive wheel which engages and is driven by the rotary grinding disk. In the present case, I provide a driving mechanism which is positively connected to the spindle, and reciprocates the same in positive timed relationship with respect to the spindle and the disk 18. In the present embodiment of my invention, the upper part of the spindle 14 is provided with a gear 255 which engages and drives a larger gear 29 carried by a vertical spindle 30, which is supported in a bearing provided in an arm 81 which is located above the bar 23, and which at one end is secured to one of the brackets 11 and at its opposite end has a bearing for the reduced upper end of the spindle 1 1 which is thus centered on said arm 31. Reciprocating movement is transmitted to the bar 23 by a horizontally arranged crank 32 which is located between the gear wheel 29 and the reciprocating bar 23, and which at one end has a pivotal connection with the bar and at its opposite end has a pivotal connection with the gear wheel 29 at an off-center point. The gear wheel 29 may have several holes or openings located different distances from the center of the gear wheel, and in any one of which the pin connecting the gear with the crank arm may be inserted. This allows for variation in the throw or length of stroke of the bar 28.

Reference is now had to Figs. .t to 8, where the details of the workholder proper are shown. The workholder 26 previously referred to, comprises a plate 33 which has a pivotal connection with the elastic strip 25, so as to permit the work to adapt itself to irregularities of the grinding disk.

In the modification disclosed in Figs. 4, 5 and 7, the plate 33 has adjustably secured to its lower side a pair of smaller plates 34 which are secured to the plate 83 by screws 35, which extend through elongated slots in the plate 33. These pin and slot connections allow the two smaller plates 3% the lower side of the plate 33 to be adjusted toward and away from each other. The plates 34: are, in the modification now being described, provided with downwardly extending pins 36, one depending from the center of each plate 34, which pins are adapted to be inserted in openings provided in the cutter blades or work 27 previously referred to. It is generally the case that blades or cutters which are adapted to be ground are provided with either a central opening or with the two openings. The structure just described is adapted to accommodate the blades having the two openings. These two pins prevent relative movement in any direction between the work and the holder, and the adjustable connection between the plates 3-4: and the plate 33 adapts the holder for blades of different widths or of different spacings of the said openlngs.

The construction shown in Figs. 6 and 8 is adapted for those blades having the single central opening. In order that blades of this character may be properly held in the holder, a centralizing pin 37 is secured in a central opening of the plate 83. Then plates 38 slightly different from the plates 34 are secured to the plate 33 in the same manner as previously described, 2'. 6., by screws which pass through elongated slots in the plate 33. The plates 38 have at their ends short downwardly extending flanges 58 constituting abntments, which together with the central pin or screw 37 which extends in the central opening of the work (here designated 27*) effectively hold the work against movement in any direction relative to the workholder.

At the same time, this workholder has the requisite range of adjustment.

Having thus described my invention, what I claim is:

1. In combination in a grinding machine, a rotary grinding disk, a reciprocable workholding member arranged at one side of the disk, and positive driving means between the said disk and the said member for reciprocating the latter, said driving means being located wholly at one side of the disk.

2. In combination in a grinding machine, a rotary grinding disk, a reciprocable workholding member at one side of the disk, a spindle extending outwardly from the disk, and mechanism connected to the said spindle i and to said member for reciprocating the member.

3. In combination in a grinding machine, a frame, a rotary grinding disk supported thereby, a reciprocable member arranged at one side of the disk, a spindle extending outwardly from the disk, and means for positively actuating said reciprocable member comprising a gear connected to the spindle, a second gear engaging the first gear, and i on i a crank arm connected to an off center polnt of the second gear and connected to said reciprocable member. 7

4:. In combination in a grinding machine, a rotary grinding disk, a work holdin support arranged at the side of the dlsk, a workholder between the disk and said support, and connected to the latter, said workholder having a pair of work-engaging members which are relatively adjustable toward and away from each other.

5. In combination in a grinding machine, a rotary grinding disk, a workholding member arranged at the side of the disk, and means connected thereto for holding the Work and for pressing the same against the 15 pin adapted to be inserted in an opening 1n 20 the work.

In testimony whereof, I hereunto aflix my signature in the presence of two witnesses.

PERCY H. ROOT.

Witnesses:

J. A. Row, E. H. STEPHENS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

